The producer of the No Stone Unturned documentary and a journalist involved in the film have been arrested in connection with the suspected theft of confidential documents held by the Police Ombudsman of Northern Ireland relating to the Loughinisland massacre.

The producer of the No Stone Unturned documentary and a journalist involved in the film have been arrested in connection with the suspected theft of confidential documents held by the Police Ombudsman of Northern Ireland relating to the Loughinisland massacre.

The documents relate to a police investigation into the murder of six men at Loughinisland in 1994.

Solicitors representing both Mr Birney and Mr McCaffrey have also confirmed their detention to the Press Association.

A spokesperson for Fine Point Films, who made the documentary, told the BBC: "We can confirm that officers from the PSNI and Durham Constabulary are currently speaking to our team and until that process is concluded we cannot make any further comment."

Both journalists were key players in uncovering material regarding the murders in 1994 and allegations of collusion linked to the killings.

Officials from the Ombudsman office reported the theft to PSNI, who in turn asked Durham Constabulary to conduct an independent investigation.

Trevor Birney from Northern Ireland-based Fine Point Films

Detectives from Durham Constabulary, supported by officers from the PSNI, executed search warrants at three properties in the Belfast area on Friday.

Two residential properties and a business premises were searched.

Police said two men, aged 51 and 48, were arrested on suspicion of theft during this operation on Friday morning and are currently being questioned at Musgrave Police Station.

A number of documents and computer equipment seized during the raids will be examined by specialist officers over the coming days.

The inquiry centres on the theft of sensitive material, which was used in a documentary film re-examining the 1994 murders.

Six men were shot dead inside the bar while watching Ireland play Italy (PA)

A spokesman for Durham Constabulary said: “This morning’s arrests are a significant development in what has been a complex investigation.

“The terms of reference given to our inquiry were clear in that the investigation is solely into the alleged theft of material from PONI.

“The theft of these documents potentially puts lives at risk and we will follow the evidence wherever it leads us.”

A spokeswoman for the Police Ombudsman's Office said: “This is a matter for Durham Constabulary and it would be inappropriate to comment while their investigation is ongoing.”

Six people were killed on June 18 1994 when loyalist gunmen burst into a bar in Loughinisland, Co Down, and opened fire on customers.

The UVF terrorists struck as football fans watched the Republic of Ireland team play in the 1994 Fifa World Cup.